1. Field of the Invention
The present invention relates to a computer aided engineering (CAE) system for numerically simulating physical phenomena through a numerical analysis using a computer and more particularly, to an apparatus for preparing an analytic model used for numerical analysis from a profile model representing an object to be analyzed.
2. Description of the Related Art
For example, the following method has been known as a conventional method of preparing an analytic model from a profile model. In a profile model representing an object to be analyzed numerically, a laminate profile portion is designated. The designated profile element has planes connected thereto, of which ones having parallel geometric characteristics are extracted and planes parallel and closest to the extracted planes are specified as paired planes. Then, neutral planes are prepared in respect of the paired planes, thereby generating an analytic model. The conventional method is described in JP-A-6-259505.
In the conventional technique, for preparation of the analytic model, the profile model represented by a planar member having a thickness is replaced with planes having no thickness to prepare or generate the analytic model. Incidentally, the profile model contains various joint elements to form a product but in the conventional analytic method as above, the planar member is replaced with planes when the profile model is converted into the analytic model, with the result that the joint relation based on, for example, bolts and adhesion is lost. Accordingly, when an analysis is carried out with the analytic model, joint for putting members together is released and for example, behavior of the members under the application of a load differs from that of the product. Taking a plate-shaped member fixed to a base by adhering so as to stand uprightly thereon, for instance, adhesion is lost in the analytic model and according to the analytic model, when applied with a load in a direction parallel to the base, the plate-shaped member, which does not move essentially even under such a condition, is released from adhesion and is caused to move.
Therefore, with a view of analyzing the whole of product with high accuracy, it is necessary to prepare an analytic model properly expressing joint portions such as bolt joint or welding portions. Generally, after neutral planes (planes having no thickness) have been prepared from a profile model, a system user searches a joint portion by consulting a CAD diagram, a joint means is analytically modeled to provide a joint model which in turn is redefined at the joint portion of the analytic model in question, and the neutral plane model and the joint model are synthesized to prepare an analytic model.
In this analytic modeling of the profile model including the joint means, for the sake of preparing the analytic model including the joint means, the system user is required to search by himself or herself the joint portion and the joint model analytically modeling the joint means must be redefined, leading to a disadvantage that the more complicated the profile, the more the analytic model preparation becomes laborious and time-consuming.